What Everybody Ought to Know About LED's Applications in Fiber Optic Communication System
What Everybody Ought to Know About LED's Applications in Fiber Optic Communication System
:: Exactly why are LEDs used in fiber optic communication systems
LED represents light-emitting diode. It is a semiconductor device which converts an electric current into light.
LED has quite high light conversion efficiency and generates little heat. It possesses some characteristics making it a superb source of light for fiber optic communication systems. Stretch Ceilings Northampton
1. Small footprint: LED's small size causes it to be valuable in practical systems
2. LED's light emitting area's dimensions are much like optical fiber's core (50um or 62.5um for multimode fibers). This really is crucial for coupling the emitted light into fiber core.
3. LED can be turned on and off at very high speed. This is whats called modulation which can be essential for digital communication systems
4. LED has very long life within the array of 80,000 to 100,000 hours. This significantly reduces communication system maintenance cost.
:: Types of LED light source
LEDs are split up into two types according to their light emitting structure: surface emitting type and edge emitting type.
Surface emitting LED emits light from their top surface. Its emitting area is big that causes poor light coupling efficiency for the fiber core. Although its optical output power is as high or perhaps regarding green edge-emitting LED, the particular coupled light into the fiber is leaner.
Edge emitting LED, alternatively, has only 30~50um emitting area, which is very comparable to multimode fiber's 50um or 62.5um core diameter. It offers high output power as well as speed performance.
Another advantage of edge emitting LED is its narrower light emission spectra compared to surface emitting type. A new form of LED, called superradiant LED, is becoming very popular in the industry because of its high power density.
:: Differences from the common indicator LED along with a fiber optic light LED
Common indicator LEDs for example those found in gadgets emit visible lights which human eyes can see(400nm to 700nm wavelength range). While LEDs found in fiber optic communications emit longer wavelength infrared light such as 850nm which human eyes cannot see directly.
Another important difference is always that LEDs used in fiber optic emit light in the much narrow angle range making coupling to optical fibers possible. Even if indicator LED light can be coupled into fibers, it really is too weak to get any use.
:: Understanding LED's characteristics
1. Peak Emitting Wavelength: This is the wavelength of which LED emits one of the most power. The most popular wavelength are 780nm, 850nm and 1310nm for fiber optic multimode communications.
2. Spectral Width: LED emits light in a wide array of wavelengths most abundant in output at the peak wavelength. A typical 850nm LED includes a spectral range of 170nm, that means it really emits light from 765nm to 935nm.
3. Rise/Fall Time: LED's rise/fall time determines how quickly it may be fired up and off. This spec has to be quick enough to meed the system's bandwidth requirement. Stretch Ceilings London
4. Power: Since a fiber optic link includes many power loss points for example fiber attenuation, connector loss, coupling loss and many more. The sunshine source must provide sufficient power and so the detector can still decode the signals with no errors.
:: Comparison between LEDs and Lasers
Some main differences exist between LEDs and lasers.
1. Laser has much narrower spectral width: DFB laser has less than 0.1nm spectral width which LED has 170nm spectral width.
2. Laser emits much higher power
3. Laser light is coherent while LED light is incoherent
4. Laser has greater modulation speed
:: Exactly why are LEDs used in fiber optic communication systems
LED represents light-emitting diode. It is a semiconductor device which converts an electric current into light.
LED has quite high light conversion efficiency and generates little heat. It possesses some characteristics making it a superb source of light for fiber optic communication systems. Stretch Ceilings Northampton
1. Small footprint: LED's small size causes it to be valuable in practical systems
2. LED's light emitting area's dimensions are much like optical fiber's core (50um or 62.5um for multimode fibers). This really is crucial for coupling the emitted light into fiber core.
3. LED can be turned on and off at very high speed. This is whats called modulation which can be essential for digital communication systems
4. LED has very long life within the array of 80,000 to 100,000 hours. This significantly reduces communication system maintenance cost.
:: Types of LED light source
LEDs are split up into two types according to their light emitting structure: surface emitting type and edge emitting type.
Surface emitting LED emits light from their top surface. Its emitting area is big that causes poor light coupling efficiency for the fiber core. Although its optical output power is as high or perhaps regarding green edge-emitting LED, the particular coupled light into the fiber is leaner.
Edge emitting LED, alternatively, has only 30~50um emitting area, which is very comparable to multimode fiber's 50um or 62.5um core diameter. It offers high output power as well as speed performance.
Another advantage of edge emitting LED is its narrower light emission spectra compared to surface emitting type. A new form of LED, called superradiant LED, is becoming very popular in the industry because of its high power density.
:: Differences from the common indicator LED along with a fiber optic light LED
Common indicator LEDs for example those found in gadgets emit visible lights which human eyes can see(400nm to 700nm wavelength range). While LEDs found in fiber optic communications emit longer wavelength infrared light such as 850nm which human eyes cannot see directly.
Another important difference is always that LEDs used in fiber optic emit light in the much narrow angle range making coupling to optical fibers possible. Even if indicator LED light can be coupled into fibers, it really is too weak to get any use.
:: Understanding LED's characteristics
1. Peak Emitting Wavelength: This is the wavelength of which LED emits one of the most power. The most popular wavelength are 780nm, 850nm and 1310nm for fiber optic multimode communications.
2. Spectral Width: LED emits light in a wide array of wavelengths most abundant in output at the peak wavelength. A typical 850nm LED includes a spectral range of 170nm, that means it really emits light from 765nm to 935nm.
3. Rise/Fall Time: LED's rise/fall time determines how quickly it may be fired up and off. This spec has to be quick enough to meed the system's bandwidth requirement. Stretch Ceilings London
4. Power: Since a fiber optic link includes many power loss points for example fiber attenuation, connector loss, coupling loss and many more. The sunshine source must provide sufficient power and so the detector can still decode the signals with no errors.
:: Comparison between LEDs and Lasers
Some main differences exist between LEDs and lasers.
1. Laser has much narrower spectral width: DFB laser has less than 0.1nm spectral width which LED has 170nm spectral width.
2. Laser emits much higher power
3. Laser light is coherent while LED light is incoherent
4. Laser has greater modulation speed